Low temperature carbonization apparatus



April 17, 1934. F. SABEL El AL 1,955,025

LOW TEMPERATURE CARBONIZATION APPARATUS Filed Nov. 6, 1930 2Sheets-Sheet 1 Fig-l INVENTORS Franz S'alel Helmull; Hanisclx BYZllezrATTORNEYS AAWM A ril 17, 1934. F A E ETAL 1,555,025

LOW TEMPERATURE GARBONIZATION APPARATUS Filed Nov. @1950 2 Sheets-Sheet2 INVENTORS Franz SaZeZ BYHwir ATTORNEYS HeYmuHL Hanisck Patented Apr.17, 1934 UNITED STATES LOW TEMPERATURE CARBONIZATION APPARATUS FranzSahel and Helmuth Hanisch, Neuroessen, Germany, assignors to I. G.Far-benindustrle Aktiengesellschaft, Frankfort on the Main,

Germany Application November 6, 1930, Serial, No. 493,807 In GermanyJuly 20, 1929 4 Claims.

The present invention relates to improvements In low temperaturecarbonization apparatus.

A process and apparatus for carrying out lowtemperature carbonization ofbituminous car- Q bonaceous materials has already been proposedaccording to which the hot gases or vapors, which may be inert or maycontain oxygen, are blown,

through the layer of fuel to be treated at 'a temperature. suitable forthe low-temperature carbonization and in such amount that the layer offuel is brought into vigorous motion on its bed, but to avoid combustionor gasification of the carbonized fuel to a higher extent than isnecessary to produce the heat for carbonization.

We have now found that this process may be carried out in a speciallyadvantageous manner with inert gases in a retort provided with severalgrates one above the other, the grates being permeable for gases but notto any substantial degree for the carbonaceous material to becarbonized. The carbonaceous material is supplied to the uppermostgrateand passes from one grate to the other through at least oneaperture in each grate provided with closing means, such as sluicesintermittently opened, or with bucket wheels conveying the material fromone grate to the next without allowing substantial amounts of gases topass. The said apertures are arranged in the grates at opposite endsthereof to compel the carbonaceous material to pass over the grates in azigzag course and are preferably provided with tubes or hoppersextending to a height above the grate corresponding to that of thedesired thickness of the layer of carbonaceous material upon the grate,so that only the uppermost layer. of carbonaceous material can passthrough the said apertures. The said tubes or hoppers are preferablyarranged adjustable in length. The inert gases are passed into theretort from below through the series of grates and layers ofcarbonaceous material thereon at such a speed that each individual layeris set in vigorous motion.

The nature of this invention will be further described with reference tothe accompanying drawing which in Figs. 1 and 2 shows in verticalcross-section arrangements of apparatus in accordance with the presentinvention. Referring to Figure 1 in detail a-denotes a low-tempera- 50ture carbonization retort containing four grates,

. b, c, d and e, arranged one above the other. The

fuel to be subjected to low-temperature car- 'bonization, such as forexample brown coal and soft coal rich in bitumen, passes from a hopper55 I through a worm conveyer 70 onto the upper grate b. The fuel passesfrom one grate to an other through tubes n (extending upward from thegrates into the space between two grates) combined with conduits qextending downward from the grates and provided with bucket wheels h andis finally removed through an outlet m and a worm conveyer 12 after ithas been subjected to low-temperature carbonization. A burner serves toprepare the inert gases of combustion. The burner is provided with tubesp and o for 5 the admission of fuel gas and air or like oxidizing gases.The inert gases of combustion pass through the single grates, each ladenwith fuel, and are. withdrawn at g together with the vapors from thelow-temperature carbonization. It is 7 preferable to leave a free spaceabove each layer of carbonaceous material so that not too much dust iscarried along.

Furthermore, it is preferable to construct the grates with as great alength as possible so that the fuel has to traverse a long path whilepassing through the retort. In this manner a better exchange of heatbetween the gases and the fuel is effected.

In the said Figure 1 the regulation of the height of the layers ofcarbonaceous material on the single grates is effected by means of therotary bucket wheels h and the tubes n, but this may be effected equallywell by other means, as for example by means of sluice valves, or byautomatic means. It is essential that-the downward stream ofcarbonaceous material is so led in counter current to the ascendinginert gases over the single grates that the fuel bed is in vigorousmotion in each single stage.

With a retort constructed according to the present invention asubstantially greater efiiciency is obtained than with the systemshitherto known, and an excellent protective treatment of the vapors fromthe low-temperature carbonization and the best utilization of the heatsupplied are also obtained.

We have further found that an apparatus constructed on the hereinbeforedescribed principle is very suitable for carrying out otherheat-treatments of bituminous carbonaceous materials as for example thegasification of solid fuels.

Thus, it is especially advantageous and simple to carry out the drying,degasiflcation and gasification (for example low-temperaturecarbonization) in a shaft, for example rectangular or circular, so thatthe singleprocesses are carried out separate from each other on thehorizontal or slightly inclined superimposed grates which are permeablefor gas but substantially impermeable 11 bucket wheel F4.

for the fuel, the hot gases flowing through the grates from the bottomto the top while the fuel flows in counter current to the gases over thesingle grates from the top to the bottom through suitable openingdevices. The fuel spreads itself out on the single grates in such amanner that there is a large gas space between the surface of the fueland the grate lying next above it.

By working in this simple manner an accurate control over the singleindependent processes of drying, degasification and gasification isobtained. In this manner it is possible to carry out each of the threeprocesses independently under the most favorable conditions, as forexample of temperature, and still to retain the combination of thedifferent processes in one shaft. The juxtaposition and confusion of thesingle processes, such as is possible for example in a shaft lowtemperature producer with or without low temperature carbonizationinsertions or attachments by reasons of the formation of grooves orchannels in the bed of fuel, is entirely avoided according to thepresent invention.

The fuel slides from one grate to the next for example through sluices,rotary bucket wheels, mushroom valves and the like. When thecrosssection of the grates is of large dimensions it is preferable tomove the fuel on the single grates in order to produce beds having asuniform a thickness as possible. This may be effected for example byblowing in the air for the gasification or the hot producer orscavenging gases which flow through the shaft upwards in such a quantityas to keep the fuel in active movement on its bed or to whirl up anddown, but to avoid combustion or gasification of the fuel to a higherextent than is necessary to produce the heat for carbonization. a

Figure 2 of the accompanying drawings represents a vertical section ofan apparatus which is particularly suitable for carrying out the drying, degasification and gasificati'on in one shaft, the single processestaking place separate from each other.

Referring to Figure 2 in detail S denotes a shaft which is divided intoseveral chambers by horizohtal grates R1, R2, R3 and R4. The fuel, forexample brown coal, is sluiced in in the usual manner from a receptacleY by means of a hopper X and bucket wheel Z and flows in a horizontaldirection over the grate R1. The fuel passes through a rotary bucketwheel F1 onto the grate R2 and from this through a rotary bucket wheelF2 on to the grate R3. Finally the fuel passes through a rotary bucketwheel F3 on to the gasifying grate R4. The ash 'of the coal gasified onthe grate R4 is removed through a rotary The grates R1 and R2 act asdrying zones. On the grate R3 the coal passes through the lowtemperature carbonization zone while the grate R4 constitutes the bottomof a lignite coke producer which may be operated with any desiredtemperature by means of a gasify-' ing agent such as air, carbondioxide, steam or mixtures of these gases blown in at L. It is blown inwith such a force that the gases flowing through the shaft S keep thefuel in motion on the single grates. In this manner the thickness of thefuel bed on the single grates is kept uniform and a movement from theinlet end to the outlet end takes place. The gases leave at G. Furtheradvantages of the process according to the present invention consist forexample in that irregular distribution of temperature, the formation ofchannels and slagglng are avoided in all cases.

The grates must offer a free passage to the ascending current of gas buton the other hand must prevent the fuel passing from one grate to theone below it except through the sluices. It has been found to beespecially suitable to construct these grates by arranging fire clayplates in a thickness equal to that'of building bricks one besideanother with their edges so that a small slit of from about 0.5 to 3millimetres remains free. These grates do not allow even.finely grainedmaterial to fall through while they only offer a slight resistance tothe gases which is necessary for a uniform distribution of the gases. Ifthe fuel is completely gasified or burned on the lowermost grate, thismay have any suitable shape which ensures the removal of the ash, as forexample movable grates, grates with scraping devices and the like.

The process may be used with special advantage for example for browncoal which has been wholly or partly predried. When the material hasbeen predried to a large extent, lignite coke maybe withdrawn at F4instead of ash by only burning as much coal on the grate R4 as isnecessary for the preheating and low temperature carbonization on theremaining grates.

It is also possible, to influence the working conditions on the singlesuperimposed grates from outside besides the combustion or gasificationon the lowest grate, by leading in air, carbon dioxide and the like atanysuitable place, for

example above one or more of the lower grates of fuel, through admissionpipes C.

When employing steam or gases containin steam as the gasifying agent itis preferable to employ the steam in a highly superheated condition inorder that the gasification may be continuous. Working in this mannerrenders it possible to obtain a final gas rich in hydrogen which issuitable for many purposes and moreover the sensible heat of that partof the steam which is not converted by the gasification is utilized inan advantageous manner for the low temperature carbonization.

What we claim is:

1. An apparatus for distilling and gasifying coal comprising a retort, aplurality of superimposed grates at spaced intervals within said retort,each of said'grates covering the entire horizontal cross-sectional areaof said retort and being permeable to gases and adapted to support thecoal to be distilled, at least one conduit for said coal in each grate,the said conduits in the several grates being out of vertical alignment,closing means within said conduits, means for feeding said coal onto theuppermost grate, means for discharging the coke from the lowermostgrate, a conduit for leading gas into the bottom of said retort, and aconduit for drawing off gas at the top of said retort.

2. An apparatus for distilling and gasifying coal comprising a retort, aplurality of superimposed grates at spaced intervals within said retort,each of said grates covering the entire horizontal cross-sectional areaof said retort and being permeable to gases and adapted to support thecoal to be distilled, at least one conduit for said coal in each grate,the said conduits in the several grates being out of vertical alignment,closing means within said conduits, means for feeding said coal onto theuppermost grate, means for discharging the coke from the lowermostgrate, a conduit for leading gas into the bottom of said retort, aconduit !or drawing on gas at the top of said retort, and a conduit forintroducing gas above at least one of the lower grates.

3. An apparatus for distilling and gasifying coal comprising a retort, aplurality of superimposed grates at spaced intervals within said retort,each of said grates covering the entire horizontal cross-sectional areaof said retort and being permeable to gases and adapted to support thecoal to be distilled, at least one conduit for said coal in each grate,the conduits in adjacent grates being at diametrically opposite sides ofsaid retort, closing means within said conduits, means for feeding saidcoal onto the uppermost grate, means for discharging the coke fromthelowermost grate, a conduit for leading gas into the bottom of saidretort, and a conduit for drawing off gas at the top of said retort.

4. An apparatus for distilling and gasifying coal comprising a retort, aplurality of superimposed grates at spaced intervals within said retort,each of said grates covering the entire horizontal cross-sectional areaof said retort and being permeable to gases and adapted to support thecoal to be distilled, at least one conduit for said coal in each grate,the said conduits in the several grates being out of vertical alignmentand each conduit extending to some predetermined distance into the spacebetween two grates, closing means within said conduits, means forfeeding said coal onto the uppermost grate, means fordischarging thecoke from the lowermost grate, a conduit for leading gas into the bottomof said retort, and a conduit for drawing off gas at the top of saidretort.

FRANZ SABEL. HELMUTH HANISCH.

